Restructured surface characterization

Surface Science of Ammonia Synthesis Structure Sensitivity of Ammonia Synthesis Kinetics of Dissociative Nitrogen Adsorption Effects of Aluminum Oxide in Restructuring Iron Single-Crystal Surfaces for Ammonia Synthesis Characterization of the Restructured Surfaces Effect of Potassium on the Dissociative Chemisorption of Nitrogen on Iron Single-Crystal Surfaces in UHV... 

Characterization of the Restructured Surfaces The observation that the AlfOv/Fe(l 10) and Al,Oy/Fe(100) become as active as the Fe(l 11) surface for ammonia synthesis suggests that new crystal orientations are being created upon restructuring the Al,Ov/Fe(l 10) and Al,0v/Fe(100) surfaces in water vapor. A sug-... 

As has been pointed out recently [10], bulk defects play a major role in a variety of surface phenomena where annealing to high temperature is necessary, e.g. during the encapsulation of Pt [11-13], in bulk-assisted re-oxidation [14,15], in restructuring and reconstruction processes [9,16], and in gas adsorption [17]. The relationship between crystal color, conductivity, bulk defects as characterized by EPR measurements, and surface structure of rutile (110) has been investigated systematically by Li et al. [10]. 

Both the most active Fe(l 11) and (210) surfaces are characterized by the existence of the so-caUed C7 sites. These sites had already been suggested to exhibit the highest activity on the basis of investigations by Mofibauer spectroscopy [12]. The activities of the Fe(l 0 0) and (110) surfaces were, on the other hand, markedly increased if these were pretreated by ammonia at 723K [13]. This procedure is associated with a pronoimced restructuring of the surface that thereby becomes more "(11 l)-like," so the... 

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